1. Field of the Invention
The present invention relates to pizza preparation and delivery vehicles.
2. Brief Description of the Prior Art.
Pizza is ubiquitous in American culture and is immensely popular among younger consumers. Pizza can be obtained in a variety of different ways. It can be cooked at home from scratch or a frozen pizza can be conveniently slipped in the oven. Some frozen pizzas now feature self-rising crust. There are numerous pizza restaurants across America, some of which are members of a national franchise such as Pizza Hut(copyright) or Little Caesar""s,(copyright). Some of these pizza restaurants offer hand-thrown fresh crust; others use par-baked crusts.
Most dine-in pizza restaurants use a gas-fired or electric tunnel oven with a conveyor belt to move the pizza through the tunnel. Because the inlet and the outlet of tunnel type ovens is open, a tremendous amount of heat is often lost in the kitchen and requires an exhaust hood to keep the temperature of the kitchen to a manageable level. In addition, these ovens are normally kept at a minimum baseline temperature which is substantially above ambient temperature when they are not cooking pizza. This allows the oven to reach cooking temperatures of 500xc2x0 F. or more without substantial warm-up time. Many of the tunnel ovens used in pizza restaurants are not particularly fuel-efficient because they must maintain this base line temperature and because of energy losses during cooking at the inlet and outlet of the tunnel. Most tunnel type ovens use blowers to impinge hot air on the top and bottom of the pizza. (These are convection type ovens.)
Another popular way for consumers to obtain pizza is delivery, at home, in the college dormitory, hotel room, or office. Domino""(copyright) pizza is a well-known national franchise that specializes in delivering pizza. Other national franchises and independent restaurants also deliver pizza. Consumers demand hot pizza and they like to have it delivered as quickly as possible after an order has been placed.
A typical delivery business will include a kitchen located in a strip center or other convenience suburban location, with a belt driven tunnel oven. When an order is placed over the telephone, fax or email, the cook typically assembles the pizza on a par-baked crust. After the pizza is run through the tunnel oven and is cooked, it is cut and placed in a box.
The delivery person then typically places the hot boxed pizza in some sort of heat retentive package and drives to the consumers location at home, at the college dorm, etc. The goal is to deliver hot pizza as quickly as possible.
Various attempts have been made to design a mobile pizza kitchen to eliminate the need for the pizza kitchen at a fixed location. For example, U.S. Pat. No. 4,632,836 assigned to Pizza Hut, Inc. describes a pizza preparation and delivery system which eliminates the need for a fixed pizza kitchen. This system uses a commissary or home base to service a fleet of vehicles, each of which can cook and deliver pizza. Customers place orders with the home base which dispatches the vehicles to the customers"" location. The vehicle disclosed in this patent is a Ford(copyright) E350 Truck with a van body mounted on the rear. This system used a driver and a cook to accomplish different tasks. The oven is a conveyor type with a belt. The applicant recommended a WEAR EVER IMPINGER(trademark) oven from Lincoln Manufacturing. A separate 110/220 volt AC generator was necessary to power the oven, the refrigerated case and other components in this system. The applicants in this prior art design recommend use of a 15 KW generator operated at 1800 RPM from Onan Corporation. Because of the heat generated by the oven, a hood is provided, which is the subject of U.S. Pat. No. 4,556,046.
The pizza crust in U.S. Pat. No. 4,632,836 was partially assembled before transit, preferably by covering the proofed dough with a layer of sauce and a layer of cheese, before storing it in the refrigerated case. Assembly and cooking of the pizza is completed by the pizza cook while the vehicle is in transit to the delivery destination. The preferred cooking temperature is about 490xc2x0 to 510xc2x0 F. and the preferred cooking time is about 10-12 minutes for 13xe2x80x3 and 15xe2x80x3 pizzas. The temperature and time could be varied from about 450xc2x0 to 550xc2x0 F. and from about 6-15 minutes. The purchase, operating and maintenance costs of the components in U.S. Pat. No. 4,632,836 ran higher than what was desirable. One factor adding to these costs was the gasoline or propane fueled generator which was included on the vehicles to supply the power needs of the refrigerated case and oven. Not only did this generator add to the purchase, operating, and maintenance costs of the vehicle, it also increased vehicle noise.
Another problem with the system disclosed in U.S. Pat. No. 4,632,836 is oven ventilation. Tunnel type conveyor belt pizza ovens typically operate at temperatures of 500xc2x0 F. and require a substantial ventilation hood because of the heat that is lost from this type of an oven at the inlet and the outlet. U.S. Pat. No. 4,643,167 also assigned to Pizza Hut, Inc. discloses an oven ventilation system for use in a pizza delivery vehicle. The oven ventilation system of this patent is described as an improvement to the ventilation system disclosed in U.S. Pat. No. 4,632,836.
By the time U.S. patent application Ser. No. 718,894 (U.S. Pat. No. 4,643,167) was filed, the preferred vehicle had been downsized from the Ford(copyright) E350 Truck with attached van body to a typical full-size van, such as the Ford xe2x80x9cEconoline(copyright).xe2x80x9d The kitchen layout was the same in U.S. Pat. No. 4,643,167 as in the predecessor, U.S. Pat. No. 4,632,836. That is, the new vehicle included a driver""s station and a kitchen area with a cook""s chair and a tunnel type, conveyor oven. The new vehicle also included a separate electrical generator.
U.S. Pat. No. 4,643,167 recommended use of an impingement type oven modified for use with LP Gas burners rather than electrical heating elements. This oven was designed with an average output of about 3,000 B.T.U. and operates with a consumption of about 1 lb. of LP gas per hour. The oven does not have a flue, but rather relies on the open slots to exhaust the combustion products into the oven ventilation system described in the patent.
Although using this smaller van resulted in a reduction of the purchase price, operating and maintenance costs, market pressures still motivated the search for a vehicle that would be less expensive to purchase, operate and maintain. In particular, it was critical to minimize the costs of this new mobile preparation and delivery system so that an operator could offer pizza at competitive prices, while achieving the same or higher profit levels as one could achieve in a conventional pizza restaurant or delivery business.
U.S. Pat. No. 4,919,477, also assigned to Pizza Hut, Inc., describes yet another attempt to deliver a compact pizza preparation and delivery vehicle. This prior art patent utilizes a small pickup truck, such as a Ford Range(copyright), Model xe2x80x9cRegular Cab 2-wheel drive.xe2x80x9d This would generally be considered a xe2x80x9cmini-pickupxe2x80x9d. This pickup truck had a payload capacity of approximately 1600 pounds and a gross vehicle weight restriction of approximately 4,000 pounds. The cargo bed of the truck is approximately 77 inches long and 54 inches wide. The engine is a 2.3 liter, 4 cylinder design. The patent recommends that the original alternator that comes from the manufacturers with this engine be replaced by a heavy duty alternator such as the one sold by Lestek Manufacturing under the designation 9135P.F. which was rated for 135 amps. The preferred oven is an impingement oven wherein heated air is impelled by high-speed fans or blowers towards the top and bottom of the pizza. This is a convection type oven. The oven was of a special design using two separate chambers to allow two pizzas to be cooked simultaneously. The doors of this special oven were equipped with actuators which would automatically open the doors and bring the baked pizza out of the oven when it was cooked. This prior art patent contemplates that pizza will be cooked while the vehicle is in transit. These specially equipped doors with actuators were believed to be advantageous because it would prevent the pizza from becoming overcooked if the driver was unable to stop the vehicle or if the driver is away from the vehicle making another delivery at the conclusion of the baking cycle. In order to expedite cooking, the pizza shells were preferably covered with pizza sauce and a first layer of cheese before being loaded into the vehicle. The proximity of hot pizza and the driver""s body could result in accidental burns.
The applicants in this prior art patent recognized that one of the design challenges was the oven. In particular, it was necessary to provide an oven which took up little space, required little electric power, and provided for efficient baking of the pizzas. Another challenge was the ventilation system. The topper or camper shell over the cargo bed of the pickup truck included at least 4 vent ports to prevent overheating of the rear compartment.
This prior art patent had two receiving areas for the pizza pans so that a separate pan could be used to cook each pizza. It also discloses use of a hot water tank and hand pump-operated sink for sanitation purposes.
The pizza preparation and delivery system disclosed in U.S. Pat. No. 4,919,477 included a fleet of vehicles which worked from a common home base. The home base is adapted to receive pizza delivery orders from customers. The home base then dispatches the orders to the appropriate vehicle. Preferably, the particular vehicle to receive the order is selected on the basis of its current location as well as the current inventory on the vehicle. The patent teaches that selection can be made manually, or it can be made by means of a microcomputer with appropriate software and input data. Preferably, the order is sent to the vehicle over the radio and converted directly into a printed delivery order ticket as described above. Alternatively, the orders can be sent over a voice communications system. A separate commissary can be established to supply the pizza shells and toppings for the vehicles.
These prior art patents describe an array of different and complicated designs, yet a need still exists for an economical and commercially viable pizza preparation and delivery vehicle. The ovens and equipment in these prior art patents are still overly complicated, inefficient and uneconomical to operate. The continuous heat generated from these ovens is at best, difficult to deal with in the rear compartment of a mini pickup truck.
In 1997, the present applicant began experimentation with new designs for a pizza preparation and delivery vehicle. Applicant purchased a 1997 Dodge Grand Caravan(copyright) with dual sliding doors van, an electric Flashbake(trademark) oven, a Kohler(copyright) 22 horsepower engine and a 12.5 KV Gillette(copyright) alternator. The Kohler(copyright) engine and the alternator were combined to produce an AC generator. Both the Flashbake(trademark) oven and the generator were located inside of the cabin of the van without any ventilation. In order to cook pizza with this design, the rear door, and the two sliding doors needed to be opened to provide sufficient ventilation for the operator. The Kohler(copyright) engine was air-cooled, so it produced a lot of heat in the van as well as exhaust fumes from the muffler. Likewise, the Flashbake(trademark) oven, when in operation, produced heat which was not vented outside the van. This design made it difficult at best, for the operator to prepare pizza. This early prototype includes a wooden case without refrigeration to hold pizza crusts, pizza toppings and beverages. The unrefrigerated case was unsuitable for keeping the toppings, crusts and beverages cold.
Throughout 1998 and 1999, the present applicant continued to experiment with different designs. In the summer of 1999, the applicant developed a metal refrigerated case with an evaporator and condensing unit. The condensing unit generates heat and was vented to atmosphere through a duct which connected to a vent in the floor of the van. The Flashbake(trademark) oven was likewise connected to a separate duct which was vented to atmosphere through a vent in the floor of the van. This solved some, but not all of the problems.
In the summer of 1999, applicant completed a design which included a generator mounted on a carrier frame at the rear of the van. The carrier frame mounted on two support arms which fitted into a trailer hitch produced by EAZ-LIFT of Sun Valley, Calif., that has been modified for this specific purpose. This unique arrangement, developed by applicant, located the Kohler(copyright) air-cooled engine outside the van so that the rear door could be closed at all times during transit and while cooking. The heat and exhaust fumes generated by the engine did not find their way into the cabin inside the van because the generator was located outside the vehicle, thus solving all heat related problems.
After further consideration, the present applicant determined that use of a mini-pickup truck would be more economical than a van. In addition, it would be more desirable to have a belt driven generator located under the hood of the truck rather than having to fabricate a special carrier frame that connected to a specially modified hitch.
Applicant has therefore developed several designs that are more economical to assemble and/or operate than those disclosed in prior art patents. Many of the old problems have been addressed because a generator can be located under the hood of the mini-pickup truck which can be driven by the serpentine belt on the engine. The Flashbake(trademark) oven uses quartz halogen lights to produce radiant energy which contacts both the top and the bottom of the pizza. The pizza is placed on an open rack in the oven rather than a conventional pan. Other types of radiation ovens are also within the scope of this invention.
The present Flashbake(trademark) oven can cook an assembled 16xe2x80x3 or 17xe2x80x3 pizza with a par-baked crust in less than two minutes, at approximately 600xc2x0 F. Maximum throughput might be in excess of 25 pizzas per hour. After the pizza has been cooked, the quartz halogen lights turn off and the Flashbake(trademark) oven quickly returns to ambient temperatures, when not in use. The quartz halogen lights in the Flashbake oven produce both ultraviolet and infrared radiation to cook the pizza without significantly warming the surrounding air. The present invention is more economical to purchase, operate and maintain than designs shown in prior art patents, as it is simpler in design, safer to operate, and possesses a higher throughput and quicker cook time.
A mini pickup truck is fitted with a camper shell or topper over the cargo bed to define a rear compartment. A refrigerated case and a radiant type oven are positioned in the rear compartment and are accessed by lowering the tailgate and raising the rear door of the shell. The refrigerated case holds par-baked pizza shells that may be pre-coated with sauce and cheese, pizza toppings and beverages. The condensing unit of the refrigerated case is connected by a duct and vented to atmosphere through a vent located on the top of the shell. The radiation type oven is likewise connected to this duct and is vented to atmosphere through the vent located on the top of the camper shell. The radiation oven using quartz halogen lights which emit ultraviolet and infrared radiation to cook the pizza. The lights draw energy only when the oven is cooking and do not directly heat the oven""s atmosphere or interior. When the lights are switched off, the oven quickly returns to ambient temperatures.
An AC generator can be located under the hood of the vehicle and can be driven by the serpentine belt from the engine. This generator produces enough electricity to operate the oven, a refrigerated case and other auxiliary equipment. In the alternative, a diesel generator can be placed in the cargo bed of the mini-pickup truck to produce electricity for the oven and refrigerated case. In an alternative embodiment, the oven and refrigerated case are positioned in the cabin of a van. The generator is located on a carrier frame outside of the cabin. This generator likewise produces enough electricity to run the oven and the refrigerated case. In an alternative embodiment, a generator can be transversely mounted in line with the engine crankshaft under the hood of the van and can be driven by the serpentine belt from the engine. Both of these generators produce enough electricity to run the oven, the refrigerated case and auxiliary equipment. These generators produce alternating current and are fitted to the vehicle in addition to the conventional alternator found on most internal combustion engines. In other words, the mini-pickup truck and van is equipped with a alternator, and an AC generator.